Technu eh?
Having spent 12 years in a Nuclear field, I have been contaminated (Crapped up) a time or twenty. Good old duct tape, Maslin, and handi wipes work well for the most part. There's nothing about dust containing Radioactive particulates that makes it more difficult to remove than regular dust.
Mix the dust in with oil and grease, and you need some sort of surficant to break the surface tension and get underneath it to break it loose, suspend it and wipe it off. The stuff we used was a gazillion dollars a bottle because it was approved by chemistry not to pose a threat to supporting components, and was just plain old soap of some sort.
Poison Ivy? The :censored: evil crap grows like mad between Blueberry bushes, and I have some 20,000 Bushes.. I hate the stuff!
If I'm exposed, the best thing I have found is Ether. Plain old starting fluid.
Blast it immediately and dab it up with a Rag. Drop the rag in the trash, or bury it. Then wash the crap out of the point of contact with Simple green mixed 50/50 with water.
Diesel works well too, but ya have to get that off of your skin quickly as well.
The trick is to Dab the area, and not wipe.
Technu is some expensive stuff, I tried it, it works OK. Almost as good as plain ol' Simple green. It's just more Handy to have in the little bottle, than to keep an old Windex bottle of simple Green around.
The Pruning crew that I sometimes Hire, swear by Baby oil to clean the stuff off, but I think they are as immune to Poison Ivy as they are Habeneros.
I still havn't found a way to get poison Ivy out of gloves and clothes.
The technu dosn't do squat as far as I can tell.
Good topic! I'm pruning for the next several weeks, and have a few spots crusting up right now....Gawd I hate that:angrysoapbox: :censored: crap!
Stay safe!
Dingeryote